Double-layer mutual capacitive touch panel

ABSTRACT

A double-layer mutual capacitive touch panel includes a first conductive layer and a second conductive layer. The first conductive layer includes multiple electrodes arranged in an array. In each column of the array, the electrodes at the ((N*M)−1) th  row are mutually electrically connected to form a first electrodes series, and the electrodes at the (N*M) th  row are mutually electrically connected to form a second electrode series, where N is a positive integer greater than or equal to 2 and M is a positive integer greater than or equal to 1. The second conductive layer includes M mutually insulated electrode strip groups sequentially arranged along a column direction of the array. Each electrode strip group includes N electrode strips mutually electrically connected, and each electrode strip of each electrode strip group extends along a row direction of the array and overlaps the electrodes of the corresponding row.

This application claims the benefit of Taiwan application Serial No.106103157, filed Jan. 26, 2017, the subject matter of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a mutual capacitive touch panel, and moreparticularly, to a double-layer mutual capacitive touch panel having adouble-layer electrode structure.

Description of the Related Art

With the progress of technologies, touch devices formed by displays andtouch panels, capable of concurrently achieving touch control anddisplay functions to provide human-machine interactions, are extensivelyapplied in electronic products including smart phones, GPS navigatorsystems, tablet computers and laptop computers. Among various types oftouch panels, mutual capacitive touch panels featuring advantages ofhigh accuracy, multi-point touch control, high durability and a hightouch control resolution have become one mainstream touch controltechnology in the industry.

The mutual capacitive touch control technology primarily determines atouch control event through detecting a coupling capacitance changegenerated by static electricity on a touching object and touch controlunits on a touch panel, when the touching object approaches or touchesthe touch control units. The mutual capacitive touch control technology,in the aspect of structural design, is mainly categorized into twotypes—single-layer electrode structures and double-layer electrodestructures. FIG. 1 shows a top view of a conventional mutual capacitivetouch panel having a single-layer electrode structure. As shown in FIG.1, driving electrodes 12 and sensing electrodes 14 of a conventionaltouch panel 10 having a single-layer structure form one single electrodelayer, and the overall thickness of the touch panel 10 can be reduced asa result. Further, each of the sensing electrodes 14 is shaped as a longstrip, is disposed correspondingly to multiple driving electrodes 14,and generates coupling capacitance with each driving electrode 14 toindividually serve as one touch control unit. However, in order toelectrically connect the individual driving electrodes 12 to pads at theborder, there must be a conductive wire 16 between every two adjacentsensing electrodes 14 to electrically connect to each driving electrode12, such that the distance between the adjacent sensing electrodes 14cannot be reduced due to the configuration of the conductive wires 16,further limiting distances between the touch control units and adistribution density of the touch control units (i.e., a resolution ofthe touch panel). Moreover, when the touch panel 10 having asingle-layer electrode structure is disposed on a display, the sensingelectrodes 14 are entirely exposed to the display, such that the sensingelectrodes 14 may easily receive noise from the display and a poorsensitivity of touch control positioning is resulted.

FIG. 2 shows a top view of a conventional mutual capacitive touch panelhaving a double-layer electrode structure. As shown in FIG. 2, sensingelectrodes 22 and driving electrodes 24 of a touch panel 20 areindividually shaped as strips and mutually intersect to form touchcontrol units. Further, the driving electrodes 24 are disposed betweenthe sensing electrodes 22 and a display to block noise from the display.In addition, because the sensing electrodes 22 and the drivingelectrodes 24 in the double-layer electrode structure mutuallyintersect, there are no conductive wires between the sensing electrodes22 or between the driving electrodes 24, thus increasing thedistribution density of touch control units as well as simplifying adesign pattern to lower manufacturing complexities. In addition, it iseasier to design algorithms of a touch control chip for controlling thetouch panel 20 having a double-layer electrode structure than thathaving a single-layer electrode structure. Thus, the double-layerelectrode structure is commonly applied in intermediate to advancedconsumer electronic products. However, in a conventional double-layerelectrode structure, conductive wires 26 for electrically connecting thesensing electrodes 22 to pads are disposed in border regions 20 b on twosides of a touch region 20 a, in a way that the ranges of the borderregions 20 b are limited by the number of the conductive wires 26 andcannot be reduced.

SUMMARY OF THE INVENTION

The invention is directed to a double-layer mutual capacitive touchpanel having fewer conductive wires, so as to decrease the number ofconductive wires and further reduce widths of border regions on twosides of a touch region.

According to an embodiment of the present invention, a double-layermutual capacitive touch panel has a touch region and a border region,and includes a first conductive layer, a second conductive layer and aninsulation layer. The first conductive layer includes a plurality ofelectrodes arranged in an array and located in the touch region. In eachcolumn of the array, the electrodes at the ((N*M)−1)^(th) row aremutually electrically connected to form a first electrode series, andthe electrodes at the (N*M)^(th) row are mutually electrically connectedto form a second electrode series, where N is a positive integer greaterthan or equal to 2 and M is a positive integer greater than or equalto 1. The second conductive layer is disposed on the first conductivelayer, and includes M mutually insulated electrode strip groupssequentially arranged in the touch region and along a column directionof the array. Each of the electrode strip groups includes N mutuallyelectrically connected electrode strips, and each electrode strip ofeach electrode strip group extends along a row direction of the arrayand overlaps the electrodes of the one corresponding column. Theinsulation layer is disposed between the first conductive layer and thesecond conductive layer.

In the double-layer mutual capacitive touch panel of the presentinvention, the same electrode strip group and at least one firstelectrode series and the second electrode series of the same columngenerate capacitance coupling to form at least two different touchcontrol units, and the electrode strips of each of the electrode stripgroups are mutually electrically connected. As such, one electrode stripgroup may be regarded as one sensing electrode, and the at least twotouch control units need only one second conductive wire to transmit asensing signal to a second pad. Therefore, the number of secondconductive wires required by the double-layer mutual capacitive touchpanel of the present invention is decreased by a half compared to thatof a conventional double-layer mutual capacitive touch panel, furtherreducing the width of the border region for disposing the secondconductive layers.

The above and other aspects of the invention will become betterunderstood with regard to the following detailed description of thepreferred but non-limiting embodiments. The following description ismade with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 (prior art) is a top view of a conventional mutual capacitivetouch panel having a single-layer electrode structure;

FIG. 2 (prior art) is a top view of a conventional mutual capacitivetouch panel having a double-layer electrode structure;

FIG. 3 is a section view of a touch display apparatus according to anembodiment of the present invention;

FIG. 4 is a top view of a double-layer mutual capacitive touch panelaccording to a first embodiment of the present invention;

FIG. 5 is a top view of a double-layer mutual capacitive touch panelaccording to a variation of the first embodiment of the presentinvention;

FIG. 6 is a top view of a first conductive layer according to a secondembodiment of the present invention;

FIG. 7 is a top view of a second conductive layer according to thesecond embodiment of the present invention;

FIG. 8 is a top view of a double-layer mutual capacitive touch panelaccording to the second embodiment of the present invention; and

FIG. 9 is a top view of a double-layer mutual capacitive touch panelaccording to a third embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 3 shows a section view of a touch display apparatus according to anembodiment of the present invention. As shown in FIG. 3, a touch displayapparatus 100 of this embodiment includes a double-layer mutualcapacitive touch panel 102 and a display panel 104. The double-layermutual capacitive touch panel 102 may be disposed on the display panel104, and has a touch region 102 a and a border region 102 b. The touchregion 102 a includes driving electrodes and sensing electrodes, and theborder region 102 b includes connecting lines. In this embodiment, theborder region 102 b may be, for example but not limited to, surroundingthe touch region 102 a. Further, the double-layer mutual capacitivetouch panel 102 may include a first conductive layer C1 and a secondconductive layer C2 cascadingly disposed on a display surface, and thefirst conductive layer C1 and the second conductive layer C2 may bemutually insulated via an insulation layer disposed therebetween. Inthis embodiment, the double-layer mutual capacitive touch panel 102 mayfurther include a substrate 106 and two thin films 108. The firstconductive layer C1 and the second conductive layer C2 may be formed onthe thin films 108, respectively. Using two adhesion layers, thesubstrate 106 is adhered to the thin film 108 provided with the secondconductive layer C2, and the thin film 108 provided with the firstconductive layer C1 is adhered to the thin film 108 provided with thesecond conductive layer C2, forming the double-layer mutual capacitivetouch panel 102. The double-layer mutual capacitive touch panel 102 maybe adhered to the display surface through the adhesion layer, so as tohave the first conductive layer C1 and the second conductive layer C2 bedisposed between the substrate 106 and the display panel 104. The thinfilm 108 between the first conductive layer C1 and the second conductivelayer C2 may serve as an insulation layer to electrically insulate thetwo. Preferably, the first conductive layer C1, closer to the displaypanel, may include driving electrodes for transmitting driving signals,and the second conductive layer C2, closer to the touching object, mayinclude sensing electrodes for generating sensing signals. Thus, thedriving electrodes can be used to block effects of the display panel onthe sensing electrodes in addition to transmitting driving signals. Thedouble-layer mutual capacitive touch panel 102 of the present inventionis not limited to the above. In another embodiment, the first conductivelayer C1 and the second conductive layer C2 may be cascadingly anddirectly formed on the substrate 106, and an insulation layer is formedbetween the first conductive layer C1 and the second conductive layer C2to electrically insulate the two. In another embodiment, the firstconductive layer C1 and the second conductive layer C2 may also bedirectly formed on the display surface of the display panel 104, e.g.,on a color filter substrate of an LCD panel or a packaging cover plateof an OLED panel. Further, the substrate 106 may include hard substratesor flexible substrate, e.g., glass substrates, tempered glass substrate,quartz substrates, sapphire substrates, hard cover lenses, plasticsubstrates, flexible cover plates, flexible plastic substrates or thinglass substrates.

The first conductive layer C1 includes a plurality of electrodesarranged in an array and located in the touch region 102 a. In eachcolumn of the array, the electrodes at the ((N*M)−1)^(th) row aremutually electrically connected to form a first electrode series, andthe electrodes at the (N*m)^(th) row are mutually electrically connectedto form a second electrode series, where N is a positive integer greaterthan or equal to 2 and M is a positive integer greater than or equalto 1. FIG. 4 shows a top view of a double-layer mutual capacitive touchpanel according to a first embodiment of the present invention. Forillustration purposes, the thin films 108 are omitted in FIG. 4, but thepresent invention is not limited thereto. As shown in FIG. 4, N is equalto 2 in this embodiment, thereby in each column of the array, electrodesE1 at odd rows (i.e., the (2*M−1)^(th) rows) are mutually electricallyconnected to form a first electrode series 110, and electrodes E2 ateven rows (i.e., the (2*M)^(th) rows) are mutually electricallyconnected to form a second electrode series 112. The first electrodeseries 110 and the second electrode series 112 are mutually insulated,and any two adjacent electrodes E1 or E2 at the same row but differentcolumns are mutually separated and insulated such that the firstelectrode series 110 at different columns or the second electrode series112 at different columns are mutually insulated. More specifically, thefirst conductive layer C1 may further include a plurality of firstconnecting segments 114 and a plurality of second connecting segments116. Each of the first connecting segments 114 connects two adjacentelectrodes E1 in each of the first electrode series 110 (i.e., twoadjacent electrodes E1 at the same column but different odd rows), andeach of the second connecting segments 116 connects two adjacentelectrodes E2 in each of the second electrode series 112 (i.e., twoadjacent electrodes E2 at the same column but different even rows). Inthis embodiment, the first connecting segments 114 and the secondconnecting segments 116 corresponding to the electrodes E1 and E2 at thesame column are respectively disposed on two sides of the electrodes E1and E2 at the same column, e.g., respectively disposed on the left orright sides, or vice versa, thus alternatingly arranging the firstconnecting segments 114 and the second connecting segments 116 toprevent electrical connection. More specifically, the electrodes E1 andE2 at the same column are overlapping and aligned in a column directionCD of the array. Further, the first connecting segments 114, in thecolumn direction CD of the array, do not overlap the electrodes E1 ofthe corresponding first electrode series 110, and the second connectingsegments 116, in the column direction CD of the array, do not overlapthe electrodes E2 of the corresponding second electrode series 112.

Further, the second conductive layer C2 includes a plurality of mutuallyinsulated electrode strip groups 118 arranged sequentially along thecolumn direction CD of the array, and each of the electrode strip groups118 includes two electrode strips 119 mutually electrically connected.Each of the electrode strips 119 of each electrode strip group 118extends along a row direction RD of the array, and overlaps, in aperpendicular projection direction Z, the electrodes E1 or E2 at thecorresponding row. Thus, the electrode strip 119 corresponding to theelectrodes E1 at the same row may generate capacitive coupling with eachof these electrodes E1 to form a touch control unit TU1, and theelectrode strip 119 corresponding to the electrodes E2 at the same rowmay generate capacitance coupling with each of these electrodes E2 toform a touch control unit TU2 for detecting a position of the touchingobject. Because two electrode strips 119 of the same electrode stripgroup 118 are adjacent to each other, the two electrode strips 119 mayrespectively overlap the electrodes E1 and E2 of two adjacent rows,i.e., respectively generating capacitance coupling with the firstelectrode series 110 and the second electrode series 112. Thus, the sameelectrode strip group 118 may form, with the first electrode series 110and the second electrode series 112 at the same column, two differenttouch control units TU1 and TU2. In this embodiment, each of theelectrode strips 119 may be shaped as, for example but not limited to, along strip, or may be in other shapes. Further, widths of the electrodesE1 and E2 in the column direction CD of the array may be greater thanwidths of the electrode strips 119 in the column direction CD of thearray. As such, the electrodes E1 and E2 can effectively block andshield the effects that the display has on the electrode strips 119,thereby enhancing the touch control accuracy of the double-layer mutualcapacitive touch panel 102.

In this embodiment, the double-layer mutual capacitive touch panel 102may further include a plurality of first conductive wires 120 and aplurality of second conductive wires 122 disposed on the substrate 106in the border region 102 b. The first conductive wires 120 areelectrically connected to the first electrode series 110 and the secondelectrode series 112, respectively, and the second conductive wires 112are electrically connected to the electrode strips 119 of the electrodestrip groups 118, respectively. More specifically, the first conductivewires 120 and the second conductive wires 122 may be made of silver or atransparent conductive material. The first conductive wires 120 mayextend from the border region 102 b to the touch region 102 a to connectto the corresponding first connecting segments 114 or second connectingsegments 116. The first conductive wires 120 and the electrodes E1 andE2 may be formed by the same first conductive layer C1 or be formed bydifferent conductive layers. Each of the second conductive wires 122 mayinclude two branches 122 a, which are respectively connected to theelectrode strips 119 of the same electrode strip group 118. The secondconductive wires 122 and the electrode strips 119 may be formed by thesame second conductive layer C2 or be formed by different conductivelayers. The double-layer mutual capacitive touch panel 102 may furtherinclude a plurality of first pads 124 and a plurality of second pads 126disposed on the substrate 106 in the border region 102 b on the sameside of the touch region 102 a. More specifically, the first pads 124and the second pads 126 may be, for example but not limited to,respectively disposed on different thin films 108. The first pads 124are electrically connected to the first conductive wires 120,respectively, and the second pads 126 are electrically connected to thesecond conductive wires 122, respectively. As such, the electrode stripgroup 118 may be electrically connected to an external control chip viathe first pads 124, and the first electrode series 110 and the secondelectrode series 112 may be electrically connected to the externalcontrol chip via the second pads 126. Further, the second conductivewires 122 may be divided into left conductive wires 122L and rightconductive wires 122R, which are respectively disposed on two sides ofthe touch region 102 a and extend to the other side of the touch region102 b to be connected to the second pads 126. It should be noted that,the second conductive wires 122 of this embodiment, in addition toconnecting the same electrode strip group 118 to the second pads 126,are capable of further electrically connecting the electrode strips 119of the same electrode strip group 118, such that the electrode strips119 of the same electrode strip group 118 may be electrically connectedin the border region 102 b. It should be noted that the presentinvention is not limited to the above electrical connection. In anotherembodiment, the electrode strips 119 of each electrode strip group 118may also be electrically connected in the touch region 102 a. Forexample, the double-layer mutual capacitive touch panel 102 may furtherinclude a plurality of connecting segments disposed in the touch region102 a, and the connecting segments are respectively placed between theelectrode strips 119 of each of the electrode strip groups 118 toconnect the electrode strips 119. The connecting segments and theelectrode strips 119 may be formed by the same second conductive layerC2 or be formed by different conductive layers.

Further, the first electrode series 110 and the second electrode series112 may serve as different driving electrodes for individuallytransmitting a driving signal. The electrode strips 119 of each of theelectrode strip groups 118 are mutually electrically connected, therebyone electrode strip group 118 may be regarded as one sensing electrodefor generating a corresponding sensing signal due to capacitancecoupling when the corresponding electrode E1 or E2 receives the drivingsignal. For one electrode strip group 118, when touch control isperformed, the control chip transmits a driving signal to each of thefirst electrode series 110 and the second electrode series 112, and theelectrode strip group 118 may generate a corresponding sensing signalfor the driving signal corresponding to each of the first electrodeseries 110 and the second electrode series 112. Thus, one electrodestrip group 118 may generate two sensing signals respectively for twodifferent driving signals or two same driving signals at different timepoints, achieving detection by means of the two touch control units TU1and TU2. One person skilled in the art can understand that, thisoperation characteristic may be applied to all embodiments of thepresent invention, and associated details are omitted hereafter. Withthe configuration of the same electrode strip group 118 generatingcapacitance coupling with the first electrode series 110 and the secondelectrode series 112 at the same column forming two different touchcontrol units TU1 and TU2, the two touch control units TU1 and TU2 needonly one second conductive wire 122 for transmitting the sensing signalto the second pad 126. Therefore, compared to the conventionaldouble-layer mutual capacitive touch panel in FIG. 2, the number ofsecond conductive wires 122 required by the double-layer mutualcapacitive touch panel 102 can be decreased by a half, further reducingthe width of the border region 102 b in which the second conductivewires 122 are provided. Taking the double-layer mutual capacitive touchpanel 102 having 28*17 touch units as an example, there are 28 touchcontrol units TU1 and TU2 in each column, and 17 touch control units TU1and TU2 in each row. In this embodiment, the double-layer mutualcapacitive touch panel 102 needs 17 first electrodes series 110 and 17second electrode series 112 but only 14 electrode strip groups 118. Thatis to say, only 14 second conductive wires 122 connecting the electrodestrip groups 118 are needed. Further, the second conductive wires 122may be placed in the border region 102 b on the two sides of the touchregion 102 a, and so only 7 second conductive wires 122 need to beprovided in the border region 102 b on each side. Assuming that thewidth of the second conductive wires 122 is 0.1 mm and a distancebetween two adjacent conductive wires is 0.05 mm, the width of theborder region 102 b on each side is only 1.05 mm. In contrast, in aconventional double-layer mutual capacitive touch panel, one sensingelectrode and one driving electrode generate capacitive coupling to formonly one touch control unit, thereby 28 conductive wires for connectingsensing electrodes are needed, leading to a width of 0.1*14+0.05*14=2.1mm of the border region 102 b on each side. Clearly, the double-layermutual capacitive touch panel 102 of the embodiment effectively reducesthe widths of the border region 102 b on left and right sides of thetouch region 102 a. When the row direction RD of the touch panel 102 isthe horizontal direction for a display image of the display panel, theframe of the touch display apparatus 100 applied is not restricted by atotal width of the second conductive wires and may be further reduced.Particularly, when the touch display apparatus 100 is applied to a smartphone, the frame at left and right sides can be reduced to achieve analmost frame-less appearance, thus increasing the size of the displayimage without changing the dimensions of the smart phone.

The double-layer mutual capacitive touch panel of the present inventionis not limited to the above embodiment. In the first conductive layer,each column of the array is not limited to including the first electrodeseries at odd rows and second electrode series at even rows. Morespecifically, in each column of the array of the present invention, atleast the first electrode series formed by the mutually electricallyconnected electrodes at ((N*M)−1)^(th) rows, and the second electrodeseries formed by the mutually electrically connected electrodes at the(N*M)^(th) rows are included, where N is a positive integer greater thanor equal to 2, and M is a positive integer greater than or equal to 1.With respect to the first embodiment, N is equal to 2, but the presentinvention is not limited thereto. To better compare difference betweenthe first embodiment and its variations as well as other embodiments andto keep the description simple, the same components in other variationsand other embodiments are represented by the same denotations, and onlythe differences between the first embodiment and its variations anddifferences between the first embodiments and other embodiments aredescribed, with the repeated parts omitted.

In a variation of the first embodiment, as shown in FIG. 5, when N isequal to 3, in addition to the first electrode series 110 and the secondelectrode series 112, each column of the array further includes a thirdelectrode series 128. To keep the drawing clear, only one column isdepicted in FIG. 5, but the present invention is not limited thereto.Compared to the first embodiment, in a first conductive layer C1 a ofthis variation of the first embodiment, the electrodes E1 at the(3*M−1)^(th) rows are mutually electrically connected to form a firstelectrode series 110 a, and the electrodes E2 at the (3*M)^(th) rows aremutually electrically connected to form a second electrode series 112 a,and the electrodes E3 at the (3*M−2)^(th) rows are mutually electricallyconnected to form the third electrode series 128. The first electrodeseries 110 a, the second electrode series 112 a and the third electrodeseries 128 are insulated from one another. The first conductive wires120 are electrically connected to the first electrode series 110 a, thesecond electrode series 112 a and the third electrode series 128,respectively. The first conductive layer C1 a may further include aplurality of third connecting segments 130 individually connectingbetween two adjacent electrodes E3 at the same column. To mutuallyelectrically connect the two adjacent electrodes E3 at the same column,a part of the individual third connecting segments 130 is placed betweentwo adjacent electrodes E1 and E2. Correspondingly, the secondconductive layer C2 a includes M mutually insulated electrode stripgroups 118 a sequentially arranged along the column direction of thearray in the touch region 102 a. Each of the electrode strip groups 118a includes N mutually electrically connected electrode strips 119 a, andeach of the electrode strips 119 a in each electrode strip group 118 aextends along the row direction of the array and overlaps the electrodesE1, E2 or E3 of the corresponding row in a perpendicular projectiondirection Z. The second conductive wires 122 are electrically connectedto the electrode strips 119 a of each of the electrode strip groups 118a, respectively. The electrode strip 119 a corresponding to theelectrodes at the same row E1 may generate capacitance coupling witheach of these electrodes E1 and form a touch control unit TU1, theelectrode strip 119 a corresponding to the electrodes E2 at the same rowmay generate capacitance coupling with each of these electrodes E2 andform a touch control unit TU2, and the electrode strip 119 acorresponding to the electrodes E3 at the same row may generatecapacitance coupling with each of these electrodes E3 and form a touchcontrol unit TU3. Since the three touch control units TU1, TU2 and TU3of this variation of the first embodiment need only one secondconductive wire 122 for transmitting the sensing signal, the number ofthe second conductive wires 122 required by the double-layer mutualcapacitive touch panel in this variation is decreased compared to thatin the conventional double-layer mutual capacitive touch panel in FIG. 2and is also less than that in the first embodiment, thereby furthereffectively reducing the width for disposing the second conductive wires122 in the border region. Similarly, N in the present invention may alsobe set to a positive integer greater than 4 so as to reduce the width ofthe border region.

The double-layer mutual capacitive touch panel of the present inventionfurther includes other embodiments. Refer to FIG. 6 to FIG. 8. FIG. 6shows a top view of a first conductive layer according to a secondembodiment of the present invention. FIG. 7 shows a top view of a secondconductive layer according to the second embodiment of the presentinvention. FIG. 8 shows a top view of a double-layer mutual capacitivetouch panel according to the second embodiment of the present invention.To better show the patterns of the first conductive layer and the secondconductive layer, only a 4*2 array is depicted in FIG. 6, and thepattern of a second conductive layer corresponding to a 4*2 array isfurther depicted in FIG. 7. It should be noted that the presentinvention is not limited to the above examples. As shown in FIG. 6,compared to the first embodiment, first connecting segments 114′ of afirst conductive layer C1′ of this embodiment overlap, in the columndirection CD of the array, electrodes E1′ of a corresponding firstelectrode series 110′, and second segments 116′ overlap, in the columndirection CD of the array, electrodes E2′ of a corresponding secondelectrode series 112′. In this embodiment, the odd-row electrodes E1′and even-row electrodes E2′ at the same column have a shift S in thecolumn direction CD of the array, and the value of the shift is a sum ofthe width of the first connecting segments 114′ and the distance betweenthe odd-row electrodes E2′ and the corresponding first connectingsegments 114′. For example, compared to the odd-row electrodes D1′, theeven-row electrodes E2′ may be shifted towards the right, and the firstconnecting segments 114′ are respectively provided on the left side ofthe even-row electrodes E2′, and the second connecting segments 116′ arerespectively provided on the right side of the odd-row electrodes E1′.It should be noted that the present invention is not limited to theabove example. In another embodiment, the even-row electrodes E2′ mayalso be shifted towards the left, and the first connecting segments 114′may be respectively provided on the right side of the even-rowelectrodes E2′, and the second connecting segments 116′ may berespectively provided on the left side of the odd-row electrodes E1′.

As shown in FIG. 7, compared to the first embodiment, each of theelectrode strips 119′ of this embodiment includes a plurality ofcross-shaped portions CP connected in series along the row direction RDof the array to connect and form a trellis electrode strip. Tocorresponding to the electrodes E1′ and E2′ in the first conductivelayer C1′, any two adjacent electrode strips 119′ also have a shift S inthe column direction CD of the array. The second conductive layer C2′may further include a plurality of first floating electrodes FE1 and aplurality of second floating electrodes FE2. The first floatingelectrodes FE1 are individually disposed between any two adjacent andconnected electrode strips 119′, so as to increase the couplingcapacitance between the touching object and the electrode strips 119′and the amount of sensing signals generated by the electrode strips119′. More specifically, the trellis electrode strip 119′ has aplurality of recesses CA, and the first floating electrodes FE1 arerespectively disposed in the recesses CA. The second floating electrodesFE2 are located outside the recesses CA, and are individually disposedbetween two adjacent first floating electrodes FE1 between two adjacentelectrode strips 119′.

As shown in FIG. 8, in this embodiment, the two cross-shaped portions ofeach electrode strip 119′ may overlap one corresponding electrode E1′ orE2′ in the perpendicular projection direction Z, for example but notlimited to. Because the shift S of any two adjacent electrode strips 119a in the column direction CD of the array is equal to the shift S of theodd-row and even-row electrodes E1′ and E2′ at the same column, theoverlapping area of the electrode 119′ with each electrode E1′ or E2′ isequal to that with another. It is known that, each touch control unitTU′ has the same sensitivity, thus further enhancing the accuracy of thedouble-layer mutual capacitive touch panel 102′ for detecting a linearmotion of the touching object. Further, the widths of the electrodes E1′and E2′ in the column direction CD of the array may also be greater thanthe width of the cross-shaped portions CP in the column direction CD ofthe array, so as to block the effect of the display on the electrodestrips 119′. It should be noted that, the double-layer mutual capacitivetouch panel 102′ of this embodiment generates capacitance coupling usingthe cross-shaped portions CP and the corresponding electrodes E1′ orE2′, and so touch control is performed when the touching object is notin contact with the housing; i.e., for floating touch, the double-layermutual capacitive touch panel 102′ still provides good touch controlaccuracy.

In another embodiment, the odd-row electrodes E1′ and the even-rowelectrodes E2′ at the same column may not have a shift in the columndirection CD of the array. In other words, the electrodes E1′ and E2′ ateach column are aligned with one another in the column direction CD ofthe array. Further, the connecting segments 114′ of this embodiment donot overlap, in the column direction CD of the array, the electrodes E1′of the corresponding first electrode series 110′, and the secondconnecting segments 116′ do not overlap, in the column direction CD ofthe array, the electrodes E2′ of the corresponding second electrodeseries 112′.

FIG. 9 shows a top view of a double-layer mutual capacitive touch panelaccording to an embodiment of the present invention. As shown in FIG. 9,compared to the first embodiment, in the double-layer mutual capacitivetouch panel of this embodiment, each electrode strip 119″ may include aplurality of openings OP sequentially arranged along the row directionRD of the array. More specifically, each of the openings OP of eachelectrode strip 119″ may overlap one corresponding electrode E1 or E2,so as to increase the amount of sensing capacitance change when thetouching object approaches or touches the double-layer mutual capacitivetouch panel 102″ and to further enhance the touch control accuracy ofthe double-layer mutual capacitive touch panel 102″. Moreover, a secondconductive layer C2″ of this embodiment may further include a pluralityof third floating electrodes FE3, which are respectively disposed in theopenings OP and are separated from the electrode strip 119″. For examplebut not limited to, three third floating electrodes FE3 may be disposedin each opening OP. Further, the second conductive layer C2″ may furtherinclude a plurality of fourth floating electrodes FE4 disposed betweenany two adjacent electrode strips 119″ so as to increase the amount oftouch sensing with respect to the touching object. In anotherembodiment, the odd-row electrodes E1″ and the even-row electrodes E2″at the same column have a shift S in the column direction CD of thearray, and any two adjacent electrode strips 119″ also have the shift Sin the column direction CD of the array, such that the openings OP ofthe two adjacent electrode strips 119″ also have the shift S.

Same as the first embodiment, in the first conductive layer of thedouble-layer mutual capacitive touch panel of the second embodiment andthe third embodiment, each column of the array is not limited toincluding the first electrode series formed by the odd-row electrodesand is not limited to including the second electrode series formed bythe even-row electrodes. In each column of the array, the firstelectrode series formed by the mutually electrically connectedelectrodes at the ((N*M)−1)^(th) rows and the second electrode seriesformed by the mutually electrically connected electrodes at the(N*M)^(th) rows are included, where N is a positive integer greater thanor equal to 2 and M is a positive integer greater than or equal to 1.Further, the second conductive layer correspondingly includes M mutuallyinsulated electrode strip groups, and each of the electrode strip groupsincludes N mutually electrically connected electrode strips. Theremaining details are the same, and shall be omitted.

In conclusion, in the double-layer mutual capacitive touch panel of thepresent invention, the same electrode strip group and at least one firstelectrode series and the second electrode series generate capacitancecoupling to form at least two different touch control units, and theelectrode strips of each of the electrode strip groups are mutuallyelectrically connected. As such, one electrode strip group may beregarded as one sensing electrode, and the at least two touch controlunits need only one second conductive wire to transmit the sensingsignal to the second pad. Therefore, the number of second conductivewires required by the double-layer mutual capacitive touch panel of thepresent invention is decreased by a half compared to that of aconventional double-layer mutual capacitive touch panel, furtherreducing the width of the border region for disposing the secondconductive layers and achieving an almost frame-less appearance for asmart phone to which the present invention is applied.

While the invention has been described by way of example and in terms ofthe preferred embodiments, it is to be understood that the invention isnot limited thereto. On the contrary, it is intended to cover variousmodifications and similar arrangements and procedures, and the scope ofthe appended claims therefore should be accorded the broadestinterpretation so as to encompass all such modifications and similararrangements and procedures.

What is claimed is:
 1. A double-layer mutual capacitive touch panel,having a touch region and a border region, comprising: a firstconductive layer, comprising a plurality of electrodes arranged in anarray and located in the touch region, in each column of the array, theelectrodes at the ((N*M)−1)th row mutually electrically connected toform a first electrode series, the electrodes at the (N*M)th mutuallyelectrically connected to form a second electrode series, where N is apositive integer greater than or equal to 2 and M is a positive integergreater than or equal to 1; a second conductive layer, disposed on thefirst conductive layer, comprising M mutually insulated electrode stripgroups sequentially arranged in the touch region along a columndirection of the array, wherein each of the electrode strip groupscomprises N mutually electrically connected electrode strips, and eachof the electrode strips of each of the electrode strip groups extendsalong a row direction of the array and overlaps, in a perpendicularprojection direction, the electrodes at one corresponding row; and aninsulation layer, disposed between the first conductive layer and thesecond conductive layer, wherein widths of the plurality of electrodesin the column direction of the array are respectively greater thanwidths of the plurality of electrode strips in the column direction ofthe array.
 2. The double-layer mutual capacitive touch panel accordingto claim 1, further comprising a plurality of conductive wires, whichare disposed in the border region and are respectively electricallyconnected to the electrode strips of each of the electrode strip groups.3. The double-layer mutual capacitive touch panel according to claim 1,wherein the first conductive layer further comprises a plurality offirst connecting segments and a plurality of second connecting segments,each of the first connecting segments connects two adjacent of theelectrodes in the corresponding first electrode series, and each of thesecond connecting segments connects two adjacent of the electrodes inthe corresponding second electrode series.
 4. The double-layer mutualcapacitive touch panel according to claim 3, wherein the firstconnecting segments do not overlap, in the column direction of thearray, the electrodes of the corresponding first electrode series, andthe second connecting segments do not overlap, in the column directionof the array, the electrodes of the second electrode series.
 5. Thedouble-layer mutual capacitive touch panel according to claim 3, whereinthe first connecting segments overlap, in the column direction of thearray, the electrodes of the corresponding first electrode series, andthe second connecting segments overlap, in the column direction of thearray, the electrodes of the corresponding second electrode series. 6.The double-layer mutual capacitive touch panel according to claimwherein the electrodes at the ((N*M)−1)th rows and the electrodes at the(N*M)th rows at the same column have a shift in the column direction ofthe array, and the electrode strips of each of the electrode stripgroups have the shift in the column direction of the array.
 7. Thedouble-layer mutual capacitive touch panel according to claim 1, whereineach of the electrode strips comprises a plurality of cross-shapedportions sequentially connected in series along the row direction of thearray.
 8. The double-layer mutual capacitive touch panel according toclaim 7, wherein every two cross-shaped portions of the electrode stripsoverlap one corresponding of the electrodes.
 9. The double-layer mutualcapacitive touch panel according to claim 7, wherein the secondconductive layer further comprises a plurality of first floatingelectrodes individually disposed between any two adjacent of thecross-shaped portions that are connected to each other.
 10. Thedouble-layer mutual capacitive touch panel according to claim 7, whereinthe second conductive layer further comprises a plurality of secondfloating electrodes disposed between any two adjacent of the electrodestrips.
 11. The double-layer mutual capacitive touch panel according toclaim 1, wherein each of the electrode strips comprises a plurality ofopenings sequentially arranged along the row direction of the array. 12.The double-layer mutual capacitive touch panel according to claim 11,wherein each of the openings of each of the electrode strips overlapsone corresponding of the electrodes.
 13. The double-layer mutualcapacitive touch panel according to claim 11, wherein the secondconductive layer further comprises a plurality of third floatingelectrodes respectively disposed in the openings.
 14. The double-layermutual capacitive touch panel according to claim 11, wherein the secondconductive layer further comprises a plurality of fourth floatingelectrodes disposed between any two adjacent of the electrode strips.